Chocolate Chestnut Cake

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Spray 3 (9-inch) round cake pans with baking spray.

Step 2
Combine chocolate morsels and hot coffee in a medium bowl; let stand for 2 minutes and then stir until chocolate is melted, 1 to 2 minutes. Whisk in eggs, oil, sour cream, and vanilla until smooth.

Step 3
Whisk together flour, sugar, cocoa powder, salt, baking soda, and baking powder in a large bowl. Stir in egg mixture. Fold in chopped chestnuts. Divide batter evenly between prepared pans (about 2 cups per pan).

Step 4
Bake in the preheated oven until a wooden pick inserted in center comes out clean, 18 to 20 minutes. Let cool in pans about 10 minutes. Invert onto a wire rack and let cool completely, about 1 hour. Trim cooled cakes flat, if necessary.

Step 5
Beat powdered sugar, butter, and chestnut puree in a large bowl with an electric mixer on medium-high speed until filling is creamy, about 2 minutes.

Step 6
Place 1 cake layer on a cardboard round cut to the same size as cake. Spread half of the filling onto the cake layer, spreading just slightly past the edge of the layer (about 1 cup). Repeat with a second cake layer and remaining filling. Top with final cake layer. Smooth excess frosting flush with the sides of the cake. Refrigerate cake until chilled, about 20 minutes.

Step 7
Place chocolate in a 4-cup glass measuring cup with a spout for the glaze; set aside. Bring cream and corn syrup to a low simmer in a small saucepan over medium-low, stirring occasionally. Pour cream mixture over chocolate, and let stand 2 minutes. Stir glaze with a spatula until completely smooth. Let stand at room temperature, stirring occasionally, until cooled to 100 to 105 degrees F (37 to 40 degrees C), 4 to 10 minutes. Glaze should be pourable and fluid.

Step 8
Remove chilled cake from the refrigerator, and place on a wire rack or inverted bowl inside a rimmed baking sheet. Quickly pour glaze over top of cake, allowing glaze to flow down the sides, making sure cake is completely covered. A spoon can be used to scoop up and reuse glaze to drizzle and coat sides. Let stand for 1 minute, allowing excess glaze to drip off the sides. Run an offset spatula around bottom edge of cake to remove any drips. Chill cake until glaze is set, about 1 hour.